Whitehaven sign ex-Huddersfield second-rower

<img alt='Haven signing Jon Grayshon in action for Featherstone Rovers' src='http://www.newsandst...photo-1.1145006!image/1645796267.jpg_gen/derivatives/smallTeaser/1645796267.jpg' />Whitehaven have boosted their squad by signing strapping second-rower Jon Grayshon until the end of the season.